Processors

The 68000 has a 24‑bit address space, allowing access to up to 16 MB of memory. Sega's memory map for the Mega Drive allowed games to be up to 4 MB without the use of a memory mapper; games that tried to go up to 10 MB would find their memory maps crushed by the Sega CD (which took the second 4 MB block) and Sega 32X (which took 2 MB of the third 4 MB block). All devices are memory mapped.

Games using save memory also needed to have the memory in the cartridge map; larger games, such as Phantasy Star IV, used a mapper to swap out cart space for SRAM during a save.

The noise channel can play either white noise or "periodic noise" either at one of three preset frequencies or using the frequency of the third tone channel (consequently, that channel will be mute)

Can be freely accessed by both the 68000 through the VDP and the Z80 through its memory map

The cartridge connector has two pins which allow stereo sound mixing directly from cart. No game used this, however, but the 32X uses it for its PWM audio

The Mega Drive 1 has mono audio output from the TV output and stereo output from a built‑in headphone jack, plus a built‑in volume control. Future models drop the headphone jack and do stereo output from the TV output

40–64 scrolling layers: Each of the 2 tilemap planes can be split into multiple scrolling layers, 32 one-tile rows and 20 two-tile columns. Each scanline, row and column can be scrolled at different rates, and each row can be overlapped.Media:GenesisTechnicalOverview.pdf[22][24]

64 colors split into four 16‑color lines; each tile can be drawn with one of these four color lines

The first color in each line is transparent and any color of the entire palette can be used as a "background color" (when no pixels are drawn at a location); consequently the Mega Drive can display 61 colors on screen at once (unless raster effects or the Shadow/Highlight modes are used, in which case this number increases depending on the extent used)

80 bytes internal VSRAM (Vertical Scrolling RAM) — used for vertical scrolling (10‑bit words, up to 20 different vertical scroll values for each of the two scrolling playfields)Media:GenesisTechnicalOverview.pdf[9]

Blast Processing

The term Blast Processing was primarily a reference to the Mega Drive VDP graphics processor's powerful DMA controller that could handle DMA (direct memory access) operations at much faster speeds than the Super NES.[32] The Mega Drive could write to VRAM during active display and VBlank,Media:GenesisTechnicalOverview.pdf[9] and had a faster memory bandwidth than the SNES. The quicker DMA transfer rates and bandwidth gave the Mega Drive a faster performance than the SNES,[33] and helped give the Mega Drive a higher fillrate, higher gameplay resolution, faster parallax scrolling, fast data blitting, and high frame-rate with many moving objects on screen, and allowed it to display more unique tiles (background and sprite tiles) and large sprites (32×32 and higher) on screen, and quickly transfer more unique tiles and large sprites (16×16 and higher) on screen.

The Mega Drive's DMA capabilities also helped give it more flexibility, allowing the hardware to be programmed in various different ways. With DMA programming, it could replicate some of the Super NES's hardware features, such as larger 64×64 sprites (combining 32×32 sprites), background scaling and rotation (like the Sega X Board and Mode 7), and direct color (increasing colors on screen). Other DMA programmable capabilities of the Mega Drive include mid-frame palette swaps (increasing colors per scanline), sprite scaling and rotation, ray casting, bitmapframebuffers, and 3D polygon graphics; the base Mega Drive hardware (without needing any enhancement chips) could render 3D polygons with a performance comparable to the Super NES's optional Super FX enhancement chip,[34][35] which itself is significantly outperformed by the Mega Drive's optional Sega Virtua Processor (SVP) enhancement chip.